Using novel nanomaterials to combat contaminants in water

(Nanowerk News) The Graduate Student Governance Association (GSGA) has named environmental engineering doctoral candidate Changseok Han as the recipient of the 2014 University of Cincinnati Graduate Student Award for Exemplary Scholarship in the area of physical science.
In recognition of the award, Han will receive a monetary prize, a plaque and a certificate at the All University Recognition Ceremony on Sunday, April 6, 2014.
Han is being recognized for his demonstrated ability, ambition and dedication to performing high-quality research. Only one award is given annually in the area of physical science and engineering.
2014 University of Cincinnati Graduate Student Award winner Changseok Han
2014 University of Cincinnati Graduate Student Award winner Changseok Han.
Han’s doctoral studies cover the development and application of two different nanomaterials. One material is designed to monitor water contaminants of emerging concern, and another is designed to decompose them.
“The increasing spatial and temporal incidence of cyanobacteria harmful algal blooms (Cyano-HABs) in freshwater estuaries worldwide has become a growing concern among the scientific community,” Han explains. “Ohio also has seen the problem in various surface waters including Lake Erie, the Ohio River, and several other lakes in Ohio.”
Han says that the presence of harmful cyanotoxins from Cyano-HABs at high concentrations in sources of drinking water is a serious threat to health of humans and wildlife. Other contaminants such as pharmaceuticals and pesticides have gained much attention due to their adverse affects (e.g., feminization of fish and wildlife, endocrine disruption, and growth problems).
“To protect the health of humans, there are two approaches. One approach is the degradation of the toxins, and the other is monitoring the toxins in sources of drinking water. Developing highly selective and fast-responding sensors to monitor these toxins is one of the major challenges to assess the associated health risks,” he said. “In addition to developing such a biosensor, the development of reliable technologies to decompose these compounds in sources of drinking water supplies is of great interest.”
As the first part of Han’s work, the interdisciplinary and collaborative development of a multi-walled carbon nanotube (MWCNT) based-biosensor for the monitoring of a cyanotoxin microcystin-LR (MC-LR) was performed. As the second part, the decomposition of these contaminants of emerging concern by advanced oxidation processes based on titanium dioxide (TiO2) photocatalysis using UV/visible (solar) light-activated TiO2 photocatalyst was studied.
In other words, Han’s study covers developing reliable technologies both to monitor such water contaminants of emerging concern and to destroy them in water for protection of public health.
According to Han, through the studies, novel nanomaterials with unique structures and functionalities were developed and applied for environmental monitoring and remediation, with the interpretation of the results providing:
  • Innovative approaches to develop sensors for detection of MC-LR that include novel aspects of carbon nanotube (CNT) functionalization and incorporation of conjugating specific antibodies for MC-LR selectivity,
  • Meaningful sensor evaluation for detection of MC-LR in water,
  • Novel approaches to control TiO2 nanostructure and to enhance the photocatalytic activity of TiO2 under both solar and visible light illumination,
  • A better understanding on the fate of cyanotoxins and other water contaminants of emerging concern with novel TiO2-based photocatalytic nanotechnology, and
  • New methodologies to develop nanosystems for important environmental and health related applications.
  • Han says his doctoral studies can provide fundamental knowledge to develop electrochemical biosensors for monitoring a microcystin and to develop nanostructured visible light-activated TiO2 photocatalysts for water treatment and water reuse. “These studies can lead to develop different biosensors to detect different cyanotoxins as well as improve the selectivity and specificity of the sensors. The newly developed TiO2 photocatalysts could be applied for real water treatment using natural solar light.”
    He says his future work will focus on comprehensive research to develop various smart nanomaterials for the treatment of water contaminants of emerging concern such as cyanotoxins, pharmaceuticals, and pesticide in freshwater aquatic systems. “A significant effort will be devoted to various novel and effective treatment processes to purify water contaminated from such toxins in both engineered processes and in situ in the aquatic systems,” he said. “I would also like to pursue research on nutrient recovery, especially phosphate and nitrogen, input from non-point sources, which are crucial for eutrophication resulting in the occurrence of massive algal blooms in surface water.”
    After graduation, Han plans to return to his country and contribute to the education of the new generation of environmental engineers and scientists and the field in general, by pursuing an academic career.
    Source: University of Cincinnati
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